Pelted with rocks from outer space

On December 18, a meteor with an estimated diameter of 10 metres, travelling at approximately 32 kilometres per second, exploded over the Bering Sea. The meteor exploded with 10 times the strength of the atomic bomb dropped on Hiroshima in 1945 — equivalent to the energy of 173 kilotons of TNT.

The explosion went relatively unnoticed and was not reported on by scientific and general media until early March. It was recorded by the Comprehensive Nuclear Test-Ban Treaty Organization at the time, but the organization did not report on it or attempt to study it further, as it was not a nuclear threat.

The event recently surfaced in the media only after Dr. Peter Brown, a professor at Western University’s Department of Physics and Astronomy, observed the explosion in the organization’s database.

NASA then added the event to its Fireballs database, which compiles the details of such events, including their location, size, and impact energy.

The incident has led to discussion surrounding the potential threat of meteors. Their seemingly unpredictable nature makes it difficult to track them and prepare for impact if and when they occur.

The Bering Sea explosion went unnoticed because the meteor arrived at a more northerly angle than most observed events, where fewer telescopes are focused. The relative proximity to a populated area — the meteor impacted just 300 kilometres off the coast Kamchatka, Russia, a peninsula housing over 300,000 people — suggests that future meteors could pose a danger if effective monitoring is not in place.

Are we in danger?

Every day, between 80 and 100 tons of dust and small meteorites fall from space, yet the impact of larger objects is a far rarer occurrence.

A January study by Dr. Sara Mazrouei, who completed her PhD in Planetary Geology at U of T last year, and Dr. Rebecca Ghent, Associate Professor in the Department of Earth Sciences, suggests that large asteroids are colliding with Earth more frequently than before, and this change in frequency began around 290 million years ago.

While ‘asteroid’ typically refers to any celestial body composed of rock and metal which orbits the sun, the U of T study focused on rocks capable of creating craters greater than 20 kilometres in diameter.

The researchers found that the rate of collisions has more than doubled over the past 290 million years compared to the ones recorded 300–650 million years ago. However, this does not mean that collisions occur often. On average, these very large asteroids only hit Earth every few million years.

So what is out there?

Around 90 per cent of objects in our solar system that are 140 metres wide or larger have been found through NASA’s Near-Earth Objects (NEO) Observations Program.

Through this program, NASA maintains a list of large NEOs that could pose a risk to Earth, determined by factors such as the size, shape, orbit trajectory, mass, and rotational dynamics.

This list, and other planetary defence studies, are used to plan for collisions. Hypothetical efforts would focus on mitigating the effects of unpreventable impacts and implementing measures that can deflect or disrupt other NEOs.

NASA’s current stance is that there are no major threats of a crash.

Looking ahead

In 2017, NASA’s Science Definition Team reaffirmed that objects that are 140 metres in diameter or smaller would only result in regional effects on impact. Large NEOs could have sub-global effects if they are 300 metres in diameter or larger, and global effects if they are one kilometre in diameter or larger.

As of 2019, over 19,000 NEOs have been discovered, compared to 10,000 in August 2013. Over 1,500 NEOs have been discovered each year since 2015, raising the possibility that objects that could pose a threat may be discovered in the future.

Although roughly two-thirds of large NEOs are estimated to be undiscovered, NEO detection continues to improve as technology advances.

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The U of T astrophysicist toolbox

The Dunlap Institute for Astronomy & Astrophysics is a global leader in astrophysical instrumentation

U of T astronomers work with complex instrumentation, including the Dragonfly Telescope Array seen here. PHOTO COURTESY OF TEAM DRAGONFLY U OF T/YALE/HARVARD

Astronomy has progressed incredibly in the centuries since Tycho Brahe, Galileo Galilei, and Nicolaus Copernicus, and the equipment required by the professional stargazer today far exceeds the capabilities of their primitive telescopes.

Luckily for space scholars at the University of Toronto, the Dunlap Institute for Astronomy & Astrophysics is at the forefront of astrophysical instrumentation development.

While it would take a textbook to explore allthe dazzling devices devised in part or whole at U of T, what follows is a glimpse at the instumentation being worked on right now.

What is a telescope?

What many people call telescopes are rarely used for research nowadays. The technology used frequently by amateurs and enthusiasts in the familiar lens-and-mirror tubes are largely obsolete in academia.

Though there are exceptions, such telescopes are largely used by amateur astronomers and enthusiasts.

Information in nature travels in waves, and some of the most useful waves are found on the electromagnetic spectrum. We perceive waves in the middle of the spectrum as colours, while radio waves have longer wavelengths and gamma rays and X-rays have shorter wavelengths.

Detecting different kinds of waves with different kinds of telescopes provides different kinds of knowledge about the cosmos. For example, much like how Hollywood spies use infrared goggles to detect human heat, infrared telescopes can be used to detect the temperatures of celestial objects.

The Canadian Hydrogen Intensity Mapping Experiment

The Canadian Hydrogen Intensity Mapping Experiment (CHIME) is a telescope that detects extraterrestrial radio waves. Located at the Dominion Radio Astrophysical Observatory in the southern mountains of British Columbia, CHIME is mapping half of the night sky out to a distance of billions of light years, the largest volume of space ever surveyed.

The ‘hydrogen’ part of the name refers to its search for traces of neutral hydrogen, measurement of which would do much to preciscely constrain exotic theories of dark energy.

Yet there have also been other uses for CHIME.

“We’ve picked up a few other science goals along the way, from monitoring pulsars to finding Fast Radio Bursts, which have really leveraged the power of this new telescope,” said Professor Keith Vanderlinde, a Dunlap faculty member collaborating on the project, in an email.

CHIME was first put into use in September 2017, but U of T’s contribution to the instrument’s development goes back further in time.

“U of T has been involved in CHIME from the beginning, helping to plan and design the project from the ground up,” added Vanderlinde.

“During construction, our team focused on the supercomputer backend that allows the CHIME to ‘see’ the sky, converting the incoming raw radio waves into meaningful image data — processing almost [1,000 gigabytes per second] of raw data down to something more manageable — and which sits at the nexus of the many projects, producing distinct streams of data for each of them. Now that things are mostly up and running, we’re neck-deep in the commissioning and analysis efforts, to make sure we understand what it is we’re measuring.”

Canadian Initiative for Radio Astronomy

Led by Dunlap Director Professor Bryan Gaensler, the Canadian Initiative for Radio Astronomy (CIRADA) is less an experiment in itself and more of a network of projects, looking to increase Canadian participation in three telescopes: CHIME, the Karl G. Jansky Very Large Array (VLA) in New Mexico, and the Australian Square Kilometre Array Pathfinder.

The objective of CIRADA is to give Canadian astrophysicists the tools necessary to convert the massive streams of raw data from the telescopes into easy-to-use catalogues and photographs so that scientists and members of the public can explore the data sets and contribute to discoveries.

Contributing to the VLA Sky Survey (VLASS), U of T is leading the charge with CIRADA by focusing on analyzing cosmic magnetism.

“The VLASS is allowing three types of experiments with radio waves: mapping the emission from black holes, looking for explosions, and studying cosmic magnetism,” explained Gaensler in an email toThe Varsity.

“As part of CIRADA, the U of T team is taking the images coming out of VLASS, and converting them into maps of magnetism in space, a bit like the simple maps of magnetism you probably made in high school by sprinkling iron filings around a toy magnet.”

Dragonfly

An example of a ‘classic’ telescope, the Dragonfly Telescope Array began with the simple idea of latching together a number of commercially available camera lenses.

The brainchild of Dunlap’s Professor Roberto Abraham, the array was originally commisioned in 2013 with three Canon 400-millimetre lenses, the same type used at events like the FIFA World Cup. Instead of viewing football, the array was placed side by side and pointed up at the night sky to look for galaxies.

Today, the array has grown to 48 lenses, each modified to remove unwanted light. It is the world’s largest array composed solely of refracting telescopes, in contrast to the more popular reflecting telescope.

While simpler in concept, Dragonfly is by no means less useful than its larger, more complex counterparts.

Its multiple lenses act as filters and are useful in detecting faint objects as the filters produce accurate images devoid of optical noise.

Earlier this year, the array discovered what appeared to be a galaxy devoid of dark matter, an element previously thought to be ubiquitous in all galaxies.

Gemini Infrared Multi-Object Spectrograph

Infrared astronomers are stargazers working at higher frequencies than radio, but still at lower frequencies than visible light.

The Gemini Infrared Multi-Object Spectrograph (GIRMOS) is U of T’s largest current contribution to the field of infrared astronomy.

Led by Dunlap’s Professor Suresh Sivanandam, GIRMOS is a spectrograph that separates the input it detects into its component wavelengths and records said components.

“GIRMOS is a one-of-a-kind scientific instrument specially designed to study very distant galaxies that are billions of light years away,” said Sivanandam in an email toThe Varsity. “These galaxies are so small in the sky that we need to use cutting-edge optical technology, called adaptive optics, to get high resolution images of these objects. With GIRMOS, we will be able to study in detail how these galaxies look like and how they form their stars. This will help us piece together how our own galaxy formed.”

The project is based on data received by the Gemini Observatory, which has two telescopes in Hawaii and Cerro Pachon, Chile.

Despite the geographic distance, the project is a testament to Canadian ingenuity.

“GIRMOS is truly a Canadian project that has institutions that span coast-to-coast,” said Sivanandam. “It takes advantage of the well of scientific and technical expertise that exists within Canada to make this instrument a reality. This project is a pathfinder for future scientific instruments on the Thirty Meter Telescope, Canada’s next big telescope.”

Closer to home, Sivanandam also noted that “U of T has provided scientific leadership in many projects that make use of the Gemini Observatory, which has ranged from imaging planets around other solar systems to studying some of the galaxies of the early universe.”

South Pole Telescope 3G

Amundsen-Scott South Pole Station is located atop the geographic south pole, the southernmost point on Earth. Its exotic locale guarantees some of the harshest conditions known to humanity, just short of outer space.

“From February to November each year, the South Pole is inaccessible due to the harsh weather. We have two scientists called ‘winter-overs’ that stay at the station during this period, and work hard to keep the telescope running in some of the most extreme weather on the planet,” said PhD student Matt Young in an email. “The sun disappears below the horizon for 6 months, leaving them in 24/7 darkness and temperatures around -60 degrees C.”

Originally built by the United States, the station is now home to an international collection of astrophysical instruments, including the aptly-named South Pole Telescope (SPT).

The SPT detects waves in a number of wavelengths ranging from microwaves to submillimeter waves. Since the telescope’s construction in 2006, a number of cameras have been used to record said detections. The newest of these cameras is the SPT-3G, a microwave camera, the detectors for which are tested and characterised right here at U of T.

Vanderlinde, former Dunlap Fellow Dr. Tyler Natoli, and Young have been U of T’s principal contributors to the SPT.

Young travelled to the south pole in the winter of 2017–2018 to aid with installing the SPT-3G and is excited about the potential information to be gleaned from the newest camera.

“[The SPT-3G] will allow us to observe the Cosmic Microwave Background, light emitted just after the Big Bang, in more detail than ever before. We currently have a detector here in Toronto that I’ll be taking down to the South Pole with me to install in the camera,” wrote Young.

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Searching for alien worlds

In his television series Cosmos: A Personal Voyage, popular astrophysicist Carl Sagan emphasized the importance of exploring other planets to give scientists a better understanding of the rapidly changing environment on Earth.

By comparing our local climates to more extreme examples, he explained that “by exploring other worlds we safeguard this one.”

Sagan spoke those words in 1980, eight years prior to the discovery of the first exoplanet, a planet beyond our solar system. In the three short decades since astrophysicists detected the exoplanet revolving around star Gamma Cephei, the astronomical community has discovered nearly 4,000 more, with nearly 3,000 possible candidates undergoing further study.

Leading the charge is Professor Sara Seager of the Massachusetts Institute of Technology, who presented the 2018 Tuzo Wilson Lecture at the Isabel Bader Theatre on November 20.

The Tuzo Wilson Lectures are an annual event held by the Department of Physics in memory of Professor J. Tuzo Wilson, a pioneer of geophysics at U of T and in Canada and the first Director of the Ontario Science Centre. Since the establishment of the J. Tuzo Wilson Professorship in Geophysics in 1995, the incumbent professor has been annually responsible for delivering the lecture in their inaugural year, and for organizing the lecture in the years that follow.

Seager is a shining example of those who hunt for planets orbiting distant stars. Her work in improving methods of exoplanet detection and her dedicated search for an Earth-like exoplanet has even netted her the moniker of “astrophysical Indiana Jones” by NASA. So it was no surprise that almost all 500 seats in the Isabel Bader Theatre were packed for her presentation, with many U of T astro-enthusiasts jostling to hear her speak on the latest discoveries in the field.

Seager began the lecture with an introduction to what exoplanets are, displaying a number of artistic renditions, before moving into a more detailed explanation of how exactly astronomers detect the distant spheroids. She explained that most exoplanets — 78.1 per cent of them — are detected by the transiting method.

Using the transiting method, astronomers like Seager chart the brightness of several stars over extended periods of time, with regular decreases in light intensity likely explainable by the movement of an exoplanet across our view of the star.

But regular optical telescopes aren’t always suitable for such observations, and Seager continued the lecture by expounding on some of the new tools and instruments that stargazers around the globe will soon be able to take advantage of. In particular, she highlighted the recently-launched Transiting Exoplanet Survey Satellite (TESS).

“TESS is going to find more of these planets orbiting red dwarf stars — transiting planets, actually — and the goal is to map most of the sky looking at all of the bright M dwarfs stars and any other stars that fall in the field of view as well,” said Seager.

Seager also emphasized how rapidly the field is developing, with some newer ideas in exoplanet astronomy seemingly bordering on science fiction.

An audience favourite, netting hearty laughs, was the Starshot project, which is an ongoing effort to send micro-satellites buoyed by single-square-metre solar sails to nearby stars by shooting lasers at them. If successful, these “starchips” would travel at five per cent the speed of light, and reach Alpha Centauri in roughly 20 years.

While the image of lasers shooting into space to propel tiny satellites may seem ludicrous, Seager was quick to mention that “in exoplanets, the line between what is mainstream science and what is completely crazy is constantly shifting.”

There was a sense of homecoming in her delivery of the lecture, as Seager is a Toronto native and completed her Bachelor of Science with Honours in Math and Physics at U of T before continuing onto a PhD at Harvard University.

As such, her academic career has now looped around, as she was inundated with questions following the lecture from the U of T audience that she was once a part of.

The audience was composed not only of professional academics, but also of astrophiles of every age and background knowledge, inspired to become involved in the hunt for worlds beyond our own.

A time-lapse of Supernova 1987A

Yvette Cendes, a PhD student in the Dunlap Institute for Astronomy & Astrophysics, used mathematical modeling to visualize a time-lapse of the aftermath of Supernova 1987A.

Based on existing quantitative data, the time-lapse observes the supernova’s shockwave — a powerful wave that causes a star to explode in space — from 1992–2017.

Since publishing her team’sfindingsinThe Astrophysical Journal, Cendes has delivered several talks about Supernova 1987A.

The significance of the time-lapse

The team’s analyses show that the “expanding remnant” of the supernova is shaped like a three-dimensional torus, or donut, rather than a two-dimensional ring.

Cendes applied statistical and mathematical techniques to the time-lapse to show that the supernova produced a shockwave expanding outward and slamming into debris that ringed the original star before its demise.

As a result of the growing torus punching “through the ring of debris,” the supernova’s shockwave has accelerated, increasing in speed by some one thousand kilometres per second.

The team also found that the shockwave from the supernova models a classic shockwave system.

A principle similar to a shockwave can be seen when a rock creates ripples in a pond. In space, however, a shockwave operates on a much larger magnitude and causes a supernova to explode.

This explosion produces supernova remnants, which are seen in the donut-shape formation of Supernova 1987A.

The origins of Supernova 1987A

U of T astronomer Ian Shelton and telescope operator Oscar Duhalde discovered Supernova 1987A on February 24, 1987. The pair was the first to observe the death of the supergiant star and its resultant explosion from the Las Campanas Observatory in northern Chile.

While 1.6 quintillion kilometres might seem like a titanic distance, Supernova 1987A is “the closest supernova to us that we’ve observed since the invention of the telescope,” said Cendes in an interview withThe Varsity.

This helps to explain Supernova 1987A’s brightness and why it is one of the most studied objects in astronomy.

The aftermath of Supernova 1987A

Under the supervision of U of T professor Bryan Gaensler, Cendes spent nine months analyzing data from 1992 to 2017, collected from a radio telescope called the CSIRO Australia Telescope Compact Array.

Cendes’ initial challenge was learning how to translate the raw radio data from the Compact Array into images, which she eventually presented in her time-lapse.

Since this was her first time using data from the Compact Array, Cendes began by replicating previously-published images that used data from the same telescope.

She then produced her own images by analyzing the datasets used, comparing them to the published images, and refining her technique until her images resembled the published ones.

After becoming proficient in data-to-image translation, Cendes analyzed the 25-year dataset from the radio telescope in full.

While previous researchers had analyzed parts of the dataset, Cendes said that she was “the first person to go back and really see this entire stretch of time.”

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A day — or millennium — in the life of a star

PhD candidate Alysa Obertas hosts Life and Death of Stars planetarium show

It is truly a shame that light pollution prevents Torontonians from gazing at the stars because, as Alysa Obertas demonstrates, they are some of the most beautiful objects in all of existence. Admittedly, stars being beautiful isn’t exactly news. But Obertas, a PhD candidate with U of T’s Department of Astronomy & Astrophysics, breathes new life into this tired cliché in the brilliant planetarium show Life and Death of Stars.

Originally created by U of T astrophysicist and Outreach Coordinator of the Department of Mathematics Dr. Ilana MacDonald, the show is presented in the basement planetarium of the Astronomy & Astrophysics Building. Life and Death of Stars opens with a sweeping view of the Toronto skyline, familiarly devoid of stars and overwhelmingly polluted by the glaring city lights. Obertas soon shows us city dwellers what we’ve been missing by transforming a murky screen into a majestic illumination of the skies outside the city.

From there, the audience is brought on a voyage from the surface of our planet into the sprawling grounds of the cosmos. Moving from one celestial object to another, Obertas meticulously explains each astrophysical concept and fundamental law governing the birth, life, and death of stars. Notable curiosities like the red supergiant Betelgeuse and goldmine supernova SN1987A are given special attention, with their unusual traits fully exposed via high-resolution images on-screen, and a comprehensive commentary given by Obertas off-screen.

“One thing I hope audiences take away is that stars aren’t fixed — they change and evolve throughout their lifetimes,” wrote Obertas in an email to The Varsity. “Even more incredible is that as stars evolve and eventually end their lives, they create heavier elements. This material gets mixed back into surrounding clouds of gas, which new stars and planets form out of. We wouldn’t be here on Earth if it weren’t for dead stars.”

It is important to note that the experience is not at all a tedious lecture. No physics foreknowledge is required; Obertas explains everything clearly, concisely, and without technobabble. In fact, portions of the presentation have little to do with astrophysics at all as they focus on constellations and what can be seen with the naked eye. Dazzling visuals that fill the room delight children and adults, alike. “I hope that people who are curious about science, space, and astronomy attend the shows and leave with a new perspective and appreciation for our place in the universe,” said Obertas. “You don’t need to be an expert to appreciate the cosmos — we all share the night sky.”

Altogether, Obertas deftly weaves astronomy with entertainment to create an experience accessible for all educational backgrounds and recommendable for all ages. Obertas’ stunning visuals and eloquent descriptions are an excellent primer for anyone seeking a comfortable introduction to the cosmos. In both the literal and the metaphorical sense, the show is absolutely stellar.

The show is roughly an hour long and costs $10 per person. More information can be found here.

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Dunlap Institute receives $23 million in funding

$10 million will go toward new Canadian radio astronomy data centre

All-sky radio astronomy surveys can provide answers to our questions about the universe. NASA/PUBLIC DOMAIN

A total of $23 million in new funding has been awarded to members of the Dunlap Institute for Astronomy & Astrophysics at U of T. Of this, $10 million was awarded to Dunlap Director Bryan Gaensler to lead the development of a Canadian radio astronomy data centre, and $13 million was awarded to Dunlap Professor Suresh Sivanandam to implement a new infrared spectrograph for the Gemini Observatory known as the Gemini InfraRed Multi-Object Spectrograph.

The awards were announced on October 12 at the annual Canada Foundation for Innovation (CFI) Innovation Fund awards ceremony held this year at the University of Manitoba. Canadian Minister of Science Kirsty Duncan presented the awards.

The underlying goal of Gaensler’s project is to manage the enormous amounts of data generated by radio telescopes that are currently surveying the sky. In some cases, like the recently completed radio telescope, the Canadian Hydrogen Intensity Mapping Experiment (CHIME), this can be as much as one terabyte of data every second.

“The data rates are enormous,” Gaensler said in an interview with The Varsity. “The data sizes are just completely unmanageable, so big that you couldn’t even save all the raw data to disk if you wanted to — you’d have to process some of it as you go.”

These vast, previously unimaginable amounts of data are only one aspect of what Gaensler terms “21st century astronomy.” Radio astronomers are also grappling with much larger fields of view than ever before: while telescopes used to point at small, specific regions of space, they now work to map the entire sky in radio wavelength. With this comes the need for near-instantaneous response times, as the chances of observing interesting, short-lived phenomena are much greater when you move from a small window to the entire sky.

While there are countless projects that can be done with an all-sky radio astronomy survey, Gaensler spoke in particular about three big scientific questions that he hopes to answer with the observations.

“Where does magnetism in the universe come from? What are all the different types of explosions and flares that happen in the universe? And what are the processes through which gas is converted into stars? So galaxy evolution, magnetism, and time-domain astronomy.”

The mandate of the CFI Innovation Fund is to support research that allows Canada to be competitive on a global stage. With the recent completion of CHIME and as the beginning of Gaensler’s radio astronomy data centre, it is clear that Canada is poised to become one of the key players in the radio astronomy landscape.

“We’re very much at the forefront,” said Gaensler, “and there’s some particular areas like pulsars and magnetism where we really own these topics.”

“[There are] all these great discoveries that Canadian radio astronomers have made in the past. We’re building on that heritage.”

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Canada’s largest radio telescope begins map of the universe

Canada’s largest radio telescope begins map of the universe

The novel CHIME telescope is a product of a collaboration between 50 Canadian scientists. Photo Courtesty of ANDRE RENARD. DUNLAP INSTITUTE FOR ASTRONOMY AND ASTROPHYSICS

September 7, 2017 marked an important day for an all-Canadian collaboration of astronomers and astrophysicists from the University of Toronto, the University of British Columbia, McGill University, and the National Research Council of Canada. After many years of development, the Canadian Hydrogen Intensity Mapping Experiment (CHIME) began collecting data in an effort to create the largest map of the universe to date.

Located at the Dominion Radio Astrophysical Observatory just outside of Penticton, British Columbia, CHIME is the largest radio telescope in Canada. The instrument is made up of four 200-by-100-metre half-cylinders and has the computing power to process seven quadrillion computer operations every second.

According to U of T’s Dunlap Institute for Astronomy and Astrophysics, one of the collaborators on the project, the result of CHIME will be a three-dimensional map of radio waves covering half the night sky and extending billions of light years deep.

In attendance at a ceremony marking CHIME’s official launch was Minister of Science Kirsty Duncan, who installed the final piece of the telescope before it began operations. Also present was Dr. Keith Vanderlinde, a professor at the Dunlap Institute and a member of the CHIME collaboration.

With the data collected from CHIME, astronomers hope to answer a number of questions about the nature and evolution of the universe. CHIME will allow astronomers to learn more about the universe’s expansion history by shedding light on a period of time when a mysterious force known as dark energy — one of the main drivers behind the expansion of the universe — first began to play a role in the universe’s evolution.

While astronomers do know that the expansion of the universe is speeding up, many questions remain about the rate at which this is occurring and the ultimate fate that will befall the universe.

In addition to CHIME’s main scientific goal of mapping the universe and studying the universe’s expansion, the telescope will study other enigmatic radio phenomena in the sky. Back-end instrumentation installed on the telescope will allow astronomers to monitor pulsars, which are rapidly rotating remnants of long-dead giant stars that emit energy at radio wavelengths. They could provide future observational evidence of gravitational waves.

CHIME will also aid in the detection of Fast Radio Bursts (FRBs), which are short-lived but extremely powerful pulses of radio waves whose origins remain a mystery. These additional scientific goals are in collaboration with the National Radio Astronomy Observatory and scientists at the Perimeter Institute in Waterloo, Ontario.

After nearly six years of construction and $16 million invested into the project, collaborating astronomers are excited about the prospects for future scientific breakthroughs that CHIME holds.

“[CHIME] lets us do things that were previously impossible,” said Vanderlinde in a joint press release issued by the telescope’s primary collaborators. “We can look in many directions at once, run several experiments in parallel, and leverage the power of this new instrument in unprecedented ways.”

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Dunlap Institute hosts stargazing event to celebrate Canada’s 150

Space enthusiasts gather at UTSG's back campus to observe the universe beyond

U of T’s Dunlap Institute for Astronomy & Astrophysics hosted a “Canada 150 Star Party” on July 29. Around 500 stargazers came to the Back Campus Fields at UTSG to enjoy a night of unobstructed views of Jupiter, Saturn, the Moon, and satellites.

The Royal Astronomical Society of Canada (RASC) and the Fédération des astronomes amateurs du Québec sponsored similar events across the country, where the public was given a chance to take a closer look at the planets and the Moon, as well as ask astronomers and astrophysicists questions and inquire about their research.

“There’s lots of people all across Canada who are doing this at the same time, and that makes it pretty special,” said Jennifer West, a postdoctoral researcher at Dunlap and one of the organizers of the event.

“Jupiter and Saturn are the most interesting-looking through a telescope,” West continued, noting that the night was even more unique because both Saturn and Jupiter were visible. It is more common for only one of the two to be visible at a time.

The International Space Station, which orbits Earth every 90 minutes, was also spotted. “It’s just not always in a good spot for us to see,” West said. “But tonight we had a good pass where we could see it go across the sky.” Attendees also saw an iridium flare, which occurs when a communications satellite reflects sunlight toward Earth, making it very bright and easy to spot.

Eclipse glasses were distributed, along with star finders and pamphlets of information about the Star Party and the eclipse to come on August 21; U of T will be holding an eclipse party from 10:00 am to 5:00 pm at the CNE near the Princess Margaret Fountain. Canadians will only witness a partial eclipse. In Toronto, 70 per cent of the sun will be blocked.

“You probably won’t even notice it was happening because the sky still stays pretty bright,” West said. “But if you wear the proper sun protection then you can, and you’ll see that a bite is taken out of it.”

West explained that solar eclipses are fairly common, occurring about every 18 months, though they are often not widely visible. The path of totality — an approximately 100-kilometre track of the Moon’s umbral shadow across Earth — will go through parts of fourteen states in the US.

“The last total eclipse in North America was 1979, and the next one [will be] in 2024, but [then] there won’t be one until 2099,” West stated. “So if you want to see an eclipse happen twice in the same city, you have to wait about 400 years.” She encourages others to travel to the US to witness the phenomenon, though if interested parties aren’t up to crossing the border, there are several events taking place in Canadian cities.

The Department of Astronomy and Astrophysics holds monthly astronomy tours at McLennan Physical Laboratories. The RASC also organizes similar events throughout the year, and for its 150th anniversary in 2018, West said it plans to host another national star party.